A case provided with a conveying means for conveying tape-like information carrier as well as an apparatus for writing, reading or erasing information to be utilized in combination with such a case.
The invention relates to a case provided with a conveying means for conveying a tape-like information carrier, said conveying means including two reels supported in said case, wherein no rotary parts extend through the wall of said case and at least one of said reels is of such a construction that a couple may be exerted thereon by a rotary (electro) magnetic field.
Furthermore the invention relates to an apparatus for writing, reading or erasing information to be utilized in combination with such a case provided with an information carrier.
Such a case provided with a conveying means for conveying a tape-like information carrier is known from the German "Offenlegungsschrift" No. 2,062,459. This "Offenlegungsschrift" discloses a cassette provided with a sound tape accommodated on two reels, said reels being rotatably mounted in said cassette. The axes of these reels do not extend through the housing of said cassette to the exterior. Such a design has the advantage that there will be avoided a penetration of dust into the cassette through slots in the bearings and that there will not be required complicated and consequently expensive bearings for avoiding such a penetration of dust. Each one of the reels is provided with one or more pieces of ferromagnetic material. The drive of the reels is realized by the generation outside the cassette of at least one rotary magnetic field penetrating to one of the reels in the cassette, said rotary field exerting a couple on the pieces of ferromagnetic material mounted on the relative reel. Such a rotary magnetic field may be generated for instance by rotating a permanent magnet of an electromagnet outside the cassette though close to said cassette about an axis forming the extension of an axis of one of said reels. A rotary (electro) magnetic field may, however, also be generated by means of a number of coils arranged at a fixed position outside the cassette, said coils being energized alternately.
The above discussed known case has, however, the drawback that in the absence of an exterior (electro) magnetic field the reels may move freely, so that the tape-like information carrier consequently tends to get unreeled at least partially from the reels and to take a rather arbitrary position within the cassette. Upon reinstating the use of the case the tape-like information carrier may be subject to rupture or at least damage while furthermore it will not be determined in advance which part of the tape-like information carrier will be present at the station for reading.